Small samples from seven coins were subjected to quantitative analysis by atomic absorption spectrometry. The results support a revised interpretation of the contemporary documents, namely that the first-issue placks were about five-twelfths fine and that the 1471 mention of new alloyed groats referred to placks, instead of to the type of groat analyzed. The latter, at least nine-twelfths fine, may have been current for 8d. when fine groats were being issued at 12d. -- AATA